Mallard

[AshleyW]

ps hornbeam, i got so fed up of removing the gas pipe union via the cab door, at a bit of a turn each time, i split the pipe and had silicone tube over the middle portion, so i can then pull out the burner with log nosed pliers, quickly unscrew and blow throught the jet and put all back within a short time. you just need to ensure when gassing the liquid gas has not forced the silicone tube off before lighting. if you have not seen it check out my 14xx video
https://www.youtube.com/watch?v=8kyNDxqlZZA

[Andy B]

Well, it was quite a cold day (good for a nice exhaust plume though!) and the water in the tender was definitely at air temperature.
We did discuss gas temperature as a possible factor. But as it was, it was impossible to get enough heat to force the boiler up to making the pressure valves blow and demonstrate sufficient release.
The jet from the 14XX definitely allowed this.
But before trying the 14XX jet, we removed the jet, purged the line then replaced it - with no effect at all. So it definitely wasn't blocked.

It could be that these locos ideally need 2 jets - a 'summer' one and a 'winter' one. They are easily swapped on the A4s....

Andy

[AshleyW]

the pipe from the gas tank to the jet may also have foreign matter from the factory, was this tested ??

[cabbage]

Ashley there was no foreign matter in the gas pipe or jet. It simply seems to have been an undersize jet fitted in error(?)

Regards

Ralph